Data exchange and schema mappings in open and closed worlds
作者： Leonid Libkin , Cristina Sirangelo
DOI: 10.1016/J.JCSS.2010.04.010
关键词:
摘要: In the study of data exchange one usually assumes an open-world semantics, making it possible to extend instances target schemas. An alternative closed-world semantics only moves 'as much as needed' from source satisfy constraints a schema mapping. It avoids some problems exhibited by but limits expressivity mappings. Here we propose mixed approach: can designate different attributes schemas open or closed, combine additional with better behavior query answering in closed worlds. We define such mappings, and show that they cover large space solutions two extremes being known semantics. investigate mapping composition, prove trichotomy theorems, classifying their complexity based on number attributes. find conditions under which mappings compose, extending results wide range also provide for restricted classes queries guaranteeing lower complexity.
core.ac.uk
ed.ac.uk
elsevier.com
sci-hub.se 参考文章(31)
Jayant Madhavan, Alon Y. Halevy, Composing mappings among data sources very large data bases. pp. 572- 583 ,(2003) , 10.1016/B978-012722442-8/50057-4
Johann Eder, Logic and databases Proceedings of the International Summer School on Advanced topics in artificial intelligence. pp. 95- 103 ,(1992) , 10.1007/3-540-55681-8_32
Georg Gottlob, Roberto Zicari, Closed World Databases Opened Through Null Values very large data bases. pp. 50- 61 ,(1988)
Andre Hernich, Nicole Schweikardt, CWA-solutions for data exchange settings with target dependencies symposium on principles of database systems. pp. 113- 122 ,(2007) , 10.1145/1265530.1265547
Phokion G. Kolaitis, Schema mappings, data exchange, and metadata management symposium on principles of database systems. pp. 61- 75 ,(2005) , 10.1145/1065167.1065176
Tomasz Imieliński, Witold Lipski, Incomplete Information in Relational Databases Journal of the ACM. ,vol. 31, pp. 761- 791 ,(1984) , 10.1145/1634.1886
Maurizio Lenzerini, Data integration: a theoretical perspective symposium on principles of database systems. pp. 233- 246 ,(2002) , 10.1145/543613.543644
Paolo Atzeni, Nicola M. Morfuni, Functional dependencies and constraints on null values in database relations Information and Control. ,vol. 70, pp. 1- 31 ,(1986) , 10.1016/S0019-9958(86)80022-5
Witold Lipski, On semantic issues connected with incomplete information databases ACM Transactions on Database Systems. ,vol. 4, pp. 262- 296 ,(1979) , 10.1145/320083.320088
J.A. Makowsky, Y.B. Pnueli, Arity and alternation in second-order logic Annals of Pure and Applied Logic. ,vol. 78, pp. 189- 202 ,(1996) , 10.1016/0168-0072(95)00013-5